P1: SBT
0521779407-03 CUNY1086/Karliner 0 521 77940 7 June 7, 2007 19:6
Alopecia 97➣Hair pluck: forceful grasping and extraction of hair, intentionally
removing both anagen and telogen hair and then determining
ratio; test is uncomfortable and error-prone
Specific Diagnostic Tests
■Hormone studies
➣Female pattern alopecia: consider: DHEA-S, testosterone,
testosterone-estradiol-binding globulin (TeBG), prolactin
■Metabolic studies
➣TSH, Hct, Hgb, Fe,%Saturation, total Fe-binding capacity, ferritin
■Fungal tests
➣Potassium hydroxide preparation (Chlorazol Black-E, other spe-
cial forms available)
➣Fungal culture – often limited by poor collection methods, false
negatives common
Other Tests as Appropriate
■Scalp (punch) biopsy for patients with inflammatory lesions
differential diagnosis
Generalized Hair Loss
TELOGEN EFFLUVIUM:sudden stressor causes∼30% of hair follicles
to enter resting (telogen) stage (normal=10%); about 3 months later
club hairs are actively shed as new hair growth begins. Full recovery is
expected.
■Systemic
■Acute illness
■Systemic lupus erythematosus, AIDS trichopathy
■Physical stress: surgery; trauma, acute blood loss
■Hypo/hyperthyroidism – lateral eyebrow hair loss seen in hypothy-
roidism
■Childbirth
■Significant psychological stress (chronic or acute)
■Environmental
■Crash diets with inadequate protein
■Drugs – Coumarins, Heparin, propanolol, Vitamin A, multiple other
drugs associated
ANAGEN EFFLUVIUM– abrupt loss of normally growing (anagen) hair;
Up to 90% of scalp follicles may be in anagen phase, extensive hair loss
may result. Usually occurs 1–4 weeks after the insult.
■Cancer chemotherapeutic agents
■Poisoning – Thallium (rat poison), Arsenic
■Radiation therapy